Antennas are an integral and critical part of any properly functioning radio transmission and receiving system. Many systems have built in small or even hidden antennas. Other system require bigger, visible antennas. In one area of the radio system art, multiple antennas of different sizes or lengths are required. For example only and not by way of limitation. High Frequency (HF) radio transmitters and receivers use a frequency range that is very wide. That is, the frequency ranges from approximately 1.5 megahertz (MHZ) to 30 MHZ. An ideal HF transmitter will operate efficiently over that entire frequency range and transmit at maximum power output so as to provide the best communication possible. In order for this to occur, the antenna must be resonate at the selected operating frequency. This requires that the antenna must be the correct length for the selected frequency. If the antenna is not the correct length for the frequency being used, the antenna will reflect some or all of the transmitted power (radio frequency (RF) energy) back to the transmitter and will cause a reduction of power output from the transmitter. This reduction of power output can cause poor communication transmissions and the reflected RF energy may also damage the transmitter.
Today's HF transmitters and transmitters/receivers (transceivers) are fully capable of transmitting, and receiving, over the entire frequency range. As just discussed, in order to do this effectively and efficiently, the user must constantly change the length of the antenna to match the selected frequency. This requires the stock piling of antennas from as short as fifteen and one-half feet to antennas as long as three hundred twelve feet and everything in between. The Applicant has calculated that in order to be able to operate efficiently and with an acceptable amount of reflected power on all HF frequencies from 1.5 MHZ to 30 MHZ a user needs anywhere from one hundred and fifty to two hundred separate antennas. Additionally, the setting up and taking down must be done whenever a new frequency must be used. This results in users having to go outside, in inclement weather, sometimes at night and at other inconvenient and inopportune times in order to lower the current antenna to the ground, adjust it to the correct length and raise it back up. While some HF antennas and associated antenna equipment, i.e. antenna tuners, claim to work on all frequencies, they are inefficient, very large and often very expensive and truly do not work at peak efficiency and are a poor substitute for a true cut to frequency resonate antenna.
Simply put, the antenna is the weak link in the systems known in the art today. Thus, there is a need in the art for providing an antenna that is reasonably small and lightweight and which works efficiently and continuously from 1.5 MHZ to 30 MHz with very low or no reflected power and that can be adjusted by a user from the transmitter/receiver operating position. It, therefore, is an object of this invention to provide a lightweight, small adjustable antenna apparatus and method that operates efficiently over large frequency ranges and does not require the user to leave the transceiver to change antenna lengths.